A Navy F/A-18 fighter jet is seen in the background as Vice President Dick Cheney arrives to greet sailors and Marines at a rally aboard the USS John C. Stennis aircraft carrier in the Persian Gulf, Friday, May 11, 2007. (AP Photo/Gerald Herbert)

Vice President Dick Cheney used the deck of a U.S. aircraft carrier just 150 miles off Iran's coast as the backdrop Friday to warn that the United States was prepared to use its naval power to keep Tehran from disrupting oil routes or "gaining nuclear weapons and dominating this region."

Cheney's sharp warnings appeared to be part of a two-track administration campaign to push back at Iran while leaving the door open to negotiations. It was almost exactly a year ago that the United States offered to negotiate with Iran as long as it first agreed to stop enriching uranium, a decision in which Cheney, participants said, was not a major player.

Senior officials said Cheney's speech was not circulated broadly in the government before it was delivered. A senior U.S. diplomat added, "He still kind of runs by his own rules."

The speech was reminiscent of Cheney's speeches about Iraq in August 2002, which argued against sending weapons inspectors back into Iraq and laid bare the split within the administration over how to deal with Saddam Hussein. But the circumstances with Iran are quite different. U.S. officials say that so many troops are tied up in Iraq, and Iran has so much power to cause disruption there and in the oil markets, that an attack on Iran's nuclear facilities would be an enormous risk.

"This is about saber-rattling and power projection," one senior State Department official said Friday. "And who better to do it?"

When President Bush ordered the two carriers into the Persian Gulf last year, senior officials said it was part of an effort to gain some negotiating leverage. U.S. officials have also been pressing European banks and companies to avoid doing business with Iran, hoping to disrupt its efforts to recycle its oil profits.

Oil seemed to be on Cheney's mind Friday when he told 3,500 to 4,000 members of the John C. Stennis crew that Iran would not be permitted to choke off oil shipments.

"With two carrier strike groups in the Gulf, we're sending clear messages to friends and adversaries alike," he said. "We'll keep the sea lanes open. We'll stand with our friends in opposing extremism and strategic threats. We'll disrupt attacks on our own forces. We'll continue bringing relief to those who suffer, and delivering justice to the enemies of freedom. And we'll stand with others to prevent Iran from gaining nuclear weapons and dominating this region."

He told the cheering crew, "This world can be messy and dangerous, but it's a world made better by American power and American values."